This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A381029 #19 Mar 01 2025 22:48:15
%S A381029 1,1,3,16,113,955,9178,97427,1121705,13836694,181295019,2507119320,
%T A381029 36416096984,553461581406,8774534872463,144744539399484,
%U A381029 2479088917439527,44004108702467428,808171916050540308,15335535608825061803,300272362335527090277,6059534345675248667550
%N A381029 G.f. A(x) satisfies A(x) = 1/(1 - x * A(x*A(x)^2)^2).
%F A381029 Let a(n,k) = [x^n] A(x)^k.
%F A381029 a(n,0) = 0^n; a(n,k) = k * Sum_{j=0..n} binomial(2*n-j+k,j)/(2*n-j+k) * a(n-j,2*j).
%o A381029 (PARI) a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n-j+k, j)/(2*n-j+k)*a(n-j, 2*j)));
%Y A381029 Cf. A088714, A381615.
%Y A381029 Cf. A120971, A143508, A381600.
%Y A381029 Cf. A381572.
%K A381029 nonn
%O A381029 0,3
%A A381029 _Seiichi Manyama_, Mar 01 2025